Crystal holder



v. L. CHAMBERLIN CRYSTAL HOLDER Filed Feb. 1, 1924 INVENTOR.

VEE/V 2. 0771/75 [Eu/v B Y ATTORNEY.

Patented Jan. 20, 1925.

FFICE.

VERN L. CHAMBERLIN, OF PONTIAC, MICHIGAN.

CRYSTAL HOLDER.

Application filed February To all whom it may concern:

Be it known that I, VERN L. CI-IAMBERLIN, a citizen of the United States, residing at Pontiac, county of Oakland, State of Michigan, have invented a certain new and useful Improvement in Crystal Holders, and declare the following to be a full, clear, and exact description of the same, such as will enable others skilled in the art to which it pertains to make and use the same, reference being had to the accompanying drawings, which form a part of this specification.

This invention relates to crystal holders for crystal detectors and the object of the invention is to provide a crystal holder adapted to receive mounted and unmounted crystals of various shapes and sizes. Another object of the invention is to provide a crystal holder comprising an adj ustable support for the crystal and a U-shaped spring metal member adapted to hold the crystal in position on the support and also adapted to make electrical contact therewith so that when the detector wire which is connected in a circuit is applied to the crystal the circuit is closed. Another object of the invention is to providea crystal holder in which the crystal is so held that several sides thereof are exposed so that the de tector wire may be moved over the surface of the crystal without the necessity of removing the crystal and replacing it in the holder to expose the different surfaces thereof. These objects and the several novel features of the invention are hereinafter more fully described and claimed and the preferred form of construction by which these objects are attained is shown in the accompanying drawings in which Fig. 1 is a side elevation of a crystal detector showing my improved crystal holder mounted thereon.

Fig. 2 is an end elevation of the crystal delector.

Fig. 3 is a section taken on line 3-3 of Fig. 1.

Fig. 4 is an elevation of the crystal holder showing a mounted crystal therein.

As shown in Figs. 2, 3 and 4 a substantially U-shaped member 1 is provided which is formed of sheet metal such as brass, copper or other suitable metal of good electrical conductivity and this U-shaped member 1 is provided with inturned upper ends 2 adapted to engage opposite sides of the crys tal 3. A screw 4 is inserted through the 1, 1924. Serial No. 689,969.

base 5 which is formed of insulating material and through an aperture provided in the U-shaped member 1, the screw being threaded into an internally threaded sleeve 6 to bindingly engage the member 1 between the lower end of the sleeve (3 and the base 5. A screw 7 is threaded into the upper end of the sleeve 6 and is provided with a large fiat head 8 having a knurled edge by means of which the screw may be threaded into or out of the sleeve 6. As shown in Fig. 1 each upright of the Ushaped member 1 is cut away intermediate its ends so that when the uprights are spread apart they will tend to spring back to the original position and by placing the crystal on the head 8 of the screw 7 the crystal is engaged between the inturned ends 2 of the U-shaped member 1.

The opposite terminals of a receiving circuit are connected to the two binding posts 9 and 10 shown in Fig. 1 and the current flows through the post 9, brass strip 11, support 12, detector rod 13 and through the detector wire 14 to the crystal 3 where the current is rectified and passes through the U-shaped member 1 and also through the screw 7, sleeve 6, and screw a through the brass strip 15 secured to the under side 7 of the base 5 by the screw a and thence through the binding post 10 to complete the circuit, the base 5 being mounted on pads 16 to prevent the metal contacts from resting on the supporting surface. By adjusting the detector rod 13 the detector wire or cat whisker 14 may be moved over the sur face of the crystal until a sensitive point is found at which time the detector rod is left in this position. By adjusting the screw 7 and supporting head 8 the crystal may be supported in any desired position to allow the most eflicient use of the cat whisker or detector wire 14. By this construction crystals of various sizes and shapes may be easily mounted in the crystal holder and by adjustment of the screw 7 the crystal may be supported in a manner to expose the greatest surface area thereof. here a mounted crystal is used the lead or Woods metal cup 17 in which the crystal is mount-- ed, shown in Fig. 4, is positioned directly on the flat head 8 of the screw 7 and the inturned ends 2 of the U-shaped member 1 are sprung apart so as to engage the opposite sides of the cup 17, the screw 7 being ad justed at this time so that the head 8 supthat as soon as a crystal is positioned in the holder it is connected in the circuit without the necessity of tightening binding screws or taking the detector apart as is the case with detectors using an enclosed crystal.

From the foregoing description it becomes evident that the device is very simple and efiicient in operation, will not easily get out of order, is easily adjusted, is com posed of few parts and is of consequent low manufacturing cost, and provides a device which accomplishes the objects described.

Having thus fully described my invention, its utility and mode of operation, what I claim and desire to secure by Letters Patent of the United States is- 1. A crystal holder r'or radio receiving sets comprising a base, a screw extending upwardly through the base, a substantially U-shaped member having an aperture through which the screw extends, a sleeve threaded onto the said screw and securing the U-shaped member to the base and an adjusting screw threaded into the opposite end of the said sleeve and having a flat head for supporting a crystal, the U-shaped member being formed of spring metal and havsets comprising a substantially U-shaped member formed of spring metal and having inturned upper ends adapted to engage the opposite sides of a crystal, and an adjustable support for the lower side of the crys tal beneath the inturned ends of the U- shaped member;

4. A crystal holder for radio receiving sets comprising a substantially U-shaped member formed of spring metal and having intnrned upper ends, and a crystal support adjustable vertically within the U-shaped member.

A crystal holder for radio receiving sets, comprising a vertically adjustable sup port for the crystal, and a pair of spring metal members on opposite sides of the adjustable support having inturned ends adapted to hold the crystal in positionon the support.

In testimony whereof, I sign this specilication.

VERN L. OHAMBERLIN. 

